package com.zwz.controller.util;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import java.security.SecureRandom;

/**
 * * @author Alysia
 * * @createDate 2022/11/16 16:49
 * * @description
 * des加密解密工具类
 */
@Data
@Component
@ConfigurationProperties(prefix = "des")
public class DESUtils {

    private String keyString;


    /**
     * des加密
     *
     * @param data 需要加密的参数
     * @return
     * @throws Exception
     */
    public String encryptBaseDes(String data) throws Exception {

        //将自定义密钥转为字节型
        byte[] encryptKey = keyString.getBytes();

        String encryptedData = null;
        //DES算法要求一个可信任的随机数源
        SecureRandom sr = new SecureRandom();
        DESKeySpec deskey = new DESKeySpec(encryptKey);

        //创建一个密钥工厂，然后用它把DESKeySpec转换成一个SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey key = keyFactory.generateSecret(deskey);

        //加密对象
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.ENCRYPT_MODE, key, sr);

        //加密，把字节数组编码成字符串
        encryptedData = new BASE64Encoder().encode(cipher.doFinal(data.getBytes()));

        return encryptedData;
    }


    /**
     * 解密字符串
     *
     * @param desData 需要解密的参数
     * @return
     * @throws Exception
     */
    public String decryptBaseDes(String desData) throws Exception {

        //将自定义密钥转为字节型
        byte[] encryptKey = keyString.getBytes();

        String decryptedData = null;

        //DES算法要求有一个可信任的随机数源
        SecureRandom sr = new SecureRandom();
        DESKeySpec desKey = new DESKeySpec(encryptKey);

        //创建一个密钥工厂，把DESKeySpec转换成一个SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        SecretKey key = keyFactory.generateSecret(desKey);

        //解密对象
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.DECRYPT_MODE, key, sr);

        //字符串解码 ——> 字节数组，并解密
        decryptedData = new String(cipher.doFinal(new BASE64Decoder().decodeBuffer(desData)));
        return decryptedData;
    }
}
